/* SSA doesn't work well when there are dead paths */
static void removeDeadBlock(BLOCK *b)
{
if (b->pred == NULL)
{
BLOCKLIST *bl = b->succ;
while (bl)
{
unlinkBlock(bl->block, b);
bl = bl->next;
}
if (b->head != b->tail && b->head->fwd != b->tail)
{ QUAD *p = b->head->fwd;
QUAD *q = b->tail->fwd;
while (q != p)
{
if (p->dc.opcode != i_dbgblock && p->dc.opcode != i_dbgblockend
&& p->dc.opcode != i_var && p->dc.opcode != i_func)
{
RemoveInstruction(p);
}
p = p->fwd;
}
}
}
}
/* SSA doesn't work well when there are dead paths */
static void removeDeadBlock(BLOCK *b)
{
if (b->pred == NULL && !b->alwayslive)
{
BLOCKLIST *bl = b->succ;
while (bl)
{
unlinkBlock(bl->block, b);
bl = bl->next;
}
if (b->critical)
{
b->critical = FALSE;
blockArray[b->blocknum] = 0;
}
if (b->head != b->tail && b->head->fwd != b->tail)
{ QUAD *p = b->head->fwd;
QUAD *q = b->tail->fwd;
while (q != p)
{
if (p->dc.opcode != i_dbgblock && p->dc.opcode != i_dbgblockend
&& p->dc.opcode != i_var && p->dc.opcode != i_func && p->dc.opcode != i_label)
{
RemoveInstruction(p);
}
p = p->fwd;
}
}
}
}
/* Split an existing free block into two pieces, and put the fragment
(the second one along in memory) onto the relevant free list.
req_bszW is the required size of the block which isn't the
fragment. */
static
void splitChunk ( Arena* a, UInt* b, Int b_listno, UInt req_bszW )
{
Int b_bszW, frag_bszW;
b_bszW = mk_plain_bszW(get_bszW_lo(b));
vg_assert(req_bszW < b_bszW);
frag_bszW = b_bszW - req_bszW;
vg_assert(frag_bszW >= overhead_szW(a));
/*
printf( "split %d into %d and %d\n",
b_bszW,req_bszW,frag_bszW );
*/
vg_assert(bszW_to_pszW(a, frag_bszW) > 0);
unlinkBlock(a, b, b_listno);
mkInuseBlock(a, b, req_bszW);
mkFreeBlock(a, &b[req_bszW], frag_bszW,
pszW_to_listNo(bszW_to_pszW(a, frag_bszW)));
}
void* VG_(arena_malloc) ( ArenaId aid, Int req_pszB )
{
Int req_pszW, req_bszW, frag_bszW, b_bszW, lno;
Superblock* new_sb;
Word* b;
Arena* a;
void* v;
VGP_PUSHCC(VgpMalloc);
ensure_mm_init();
a = arenaId_to_ArenaP(aid);
vg_assert(req_pszB >= 0);
vg_assert(req_pszB < 0x7FFFFFF0);
req_pszW = req_pszB_to_req_pszW(req_pszB);
/* Keep gcc -O happy: */
b = NULL;
/* Start searching at this list. */
lno = pszW_to_listNo(req_pszW);
/* This loop finds a list which has a block big enough, or sets
req_listno to N_LISTS if no such block exists. */
while (True) {
if (lno == VG_N_MALLOC_LISTS) break;
/* If this list is empty, try the next one. */
if (a->freelist[lno] == NULL) {
lno++;
continue;
}
/* Scan a->list[lno] to find a big-enough chunk. */
b = a->freelist[lno];
b_bszW = mk_plain_bszW(get_bszW_lo(b));
while (True) {
if (bszW_to_pszW(a, b_bszW) >= req_pszW) break;
b = get_next_p(b);
b_bszW = mk_plain_bszW(get_bszW_lo(b));
if (b == a->freelist[lno]) break;
}
if (bszW_to_pszW(a, b_bszW) >= req_pszW) break;
/* No luck? Try a larger list. */
lno++;
}
/* Either lno < VG_N_MALLOC_LISTS and b points to the selected
block, or lno == VG_N_MALLOC_LISTS, and we have to allocate a
new superblock. */
if (lno == VG_N_MALLOC_LISTS) {
req_bszW = pszW_to_bszW(a, req_pszW);
new_sb = newSuperblock(a, req_bszW);
if (NULL == new_sb) {
// Should only fail if for client, otherwise, should have aborted
// already.
vg_assert(VG_AR_CLIENT == aid);
return NULL;
}
new_sb->next = a->sblocks;
a->sblocks = new_sb;
b = &(new_sb->payload_words[0]);
lno = pszW_to_listNo(bszW_to_pszW(a, new_sb->n_payload_words));
mkFreeBlock ( a, b, new_sb->n_payload_words, lno);
}
/* Ok, we can allocate from b, which lives in list req_listno. */
vg_assert(b != NULL);
vg_assert(lno >= 0 && lno < VG_N_MALLOC_LISTS);
vg_assert(a->freelist[lno] != NULL);
b_bszW = mk_plain_bszW(get_bszW_lo(b));
req_bszW = pszW_to_bszW(a, req_pszW);
/* req_bszW is the size of the block we are after. b_bszW is the
size of what we've actually got. */
vg_assert(b_bszW >= req_bszW);
/* Could we split this block and still get a useful fragment?
Where "useful" means that the payload size of the frag is at
least one word. */
frag_bszW = b_bszW - req_bszW;
if (frag_bszW > overhead_szW(a)) {
splitChunk(a, b, lno, req_bszW);
} else {
/* No, mark as in use and use as-is. */
unlinkBlock(a, b, lno);
/*
set_bszW_lo(b, mk_inuse_bszW(b_bszW));
set_bszW_hi(b, mk_inuse_bszW(b_bszW));
*/
mkInuseBlock(a, b, b_bszW);
}
vg_assert(req_bszW <= mk_plain_bszW(get_bszW_lo(b)));
a->bytes_on_loan
+= sizeof(Word)
* bszW_to_pszW(a, mk_plain_bszW(get_bszW_lo(b)));
if (a->bytes_on_loan > a->bytes_on_loan_max)
a->bytes_on_loan_max = a->bytes_on_loan;
# ifdef DEBUG_MALLOC
mallocSanityCheckArena(aid);
# endif
VGP_POPCC(VgpMalloc);
v = first_to_payload(a, b);
vg_assert( (((UInt)v) & 7) == 0 );
return v;
}
void VG_(arena_free) ( ArenaId aid, void* ptr )
{
Superblock* sb;
UInt* sb_payl_firstw;
UInt* sb_payl_lastw;
UInt* other;
UInt* ch;
Int ch_bszW, ch_pszW, other_bszW, ch_listno;
Arena* a;
VGP_PUSHCC(VgpMalloc);
ensure_mm_init();
a = arenaId_to_ArenaP(aid);
if (ptr == NULL) {
VGP_POPCC(VgpMalloc);
return;
}
ch = payload_to_first(a, ptr);
# ifdef DEBUG_MALLOC
vg_assert(blockSane(a,ch));
# endif
a->bytes_on_loan
-= sizeof(Word)
* bszW_to_pszW(a, mk_plain_bszW(get_bszW_lo(ch)));
sb = findSb( a, ch );
sb_payl_firstw = &(sb->payload_words[0]);
sb_payl_lastw = &(sb->payload_words[sb->n_payload_words-1]);
/* Put this chunk back on a list somewhere. */
ch_bszW = get_bszW_lo(ch);
ch_pszW = bszW_to_pszW(a, ch_bszW);
ch_listno = pszW_to_listNo(ch_pszW);
mkFreeBlock( a, ch, ch_bszW, ch_listno );
/* See if this block can be merged with the following one. */
other = ch + ch_bszW;
/* overhead_szW(a) is the smallest possible bszW for this arena.
So the nearest possible end to the block beginning at other is
other+overhead_szW(a)-1. Hence the test below. */
if (other+overhead_szW(a)-1 <= sb_payl_lastw) {
other_bszW = get_bszW_lo(other);
if (!is_inuse_bszW(other_bszW)) {
/* VG_(printf)( "merge-successor\n"); */
other_bszW = mk_plain_bszW(other_bszW);
# ifdef DEBUG_MALLOC
vg_assert(blockSane(a, other));
# endif
unlinkBlock( a, ch, ch_listno );
unlinkBlock( a, other, pszW_to_listNo(bszW_to_pszW(a,other_bszW)) );
ch_bszW += other_bszW;
ch_listno = pszW_to_listNo(bszW_to_pszW(a, ch_bszW));
mkFreeBlock( a, ch, ch_bszW, ch_listno );
}
}
/* See if this block can be merged with its predecessor. */
if (ch-overhead_szW(a) >= sb_payl_firstw) {
other_bszW = get_bszW_hi_from_last_word( ch-1 );
if (!is_inuse_bszW(other_bszW)) {
/* VG_(printf)( "merge-predecessor\n"); */
other = last_to_first( ch-1 );
other_bszW = mk_plain_bszW(other_bszW);
unlinkBlock( a, ch, ch_listno );
unlinkBlock( a, other, pszW_to_listNo(bszW_to_pszW(a, other_bszW)) );
ch = other;
ch_bszW += other_bszW;
ch_listno = pszW_to_listNo(bszW_to_pszW(a, ch_bszW));
mkFreeBlock( a, ch, ch_bszW, ch_listno );
}
}
# ifdef DEBUG_MALLOC
mallocSanityCheckArena(aid);
# endif
VGP_POPCC(VgpMalloc);
}
